The present application is a continuation application of U.S. patent application Ser. No. 13/362,186 filed on Jan. 31, 2012, by Jean-Paul Louvel, titled “METHOD OF FORMING A SWITCHED MODE POWER SUPPLY CONTROLLER DEVICE WITH AN OFF MODE AND STRUCTURE THEREFOR” which is hereby incorporated by reference in its entirety, and priority thereto for common subject matter is hereby claimed.
The present invention relates, in general, to electronics, and more particularly, to semiconductors, structures thereof, and methods of forming semiconductor devices.
Current switch mode power supply controllers seek to maintain an output voltage level within a range (e.g., within Vcc-stop and Vcc-start), and send drive signals to regulate voltage within the range. Such regulation occurs whether an initially applied load changes or not, for example if initially there can be a load voltage on the system, the system will regulate the output voltage to provide the load voltage. However if conditions change so that there can be no longer any load for period of time, typical controller systems are unable to provide an off mode that allows the output voltage to drop outside of the range while there can be little load voltage and to quickly provide regulation again when a load can be redetected. If an off-mode can be provided typically its implementation requires an additional pin to a chip configuration that prohibits a simple plug and play implementation with existing pin connections, thus making such solutions difficult to implement in unmodified systems.
Accordingly, it can be desirable to have a method of providing an off-mode in a power controller where the semiconductor configuration does not require any additional pins to implement the off-mode.